Field
The present specification generally relates to glass compositions suitable for use in 3-D forming applications and, more specifically, to ion exchangeable, Li-containing glass compositions suitable for 3-D forming.
Technical Background
Ion exchangeable glass compositions are widely used as cover glasses in many electronic devices including mobile telephones, personal media players, tablet computers and the like. The cover glasses used in these applications are generally flat and planar. As such, the cover glasses may be formed using conventional glass forming processes, such as down draw processes and/or float processes.
One limiting factor in the aesthetic design of electronic devices is the ability to shape the cover glasses to conform to curved and/or complex contours. Glass compositions which are amenable to ion exchange generally have relatively high softening points, making the glass compositions difficult to form into 3-D shapes using elevated temperature forming processes such as vacuum sagging. As a result of the relatively high softening points, the glass compositions tend to react with the material of the mold, sticking to the mold and/or degrading the mold, even when protective coatings are applied to the mold.
Accordingly, a need exists for alternative glass compositions suitable for use in elevated temperature 3-D forming processes and which are also amenable to strengthening by ion exchange processing.